Chapter 2 Fundamentals of Robotics 27
The three levels are:
• Level I—Actuator Control. The most elementary level at which
separate movements of the robot along various planes, such as the X,
Y, and Z axes, are controlled. These movements will be explained in
detail later in this chapter.
• Level II—Path Control. The path control (intermediate) level
coordinates the separate movements along the planes determined in
Level I into the desired trajectory or path.
• Level III—Main Control. The primary function of this highest control
level is to interpret the written instructions from the human programmer
regarding the tasks required. The instructions are then combined with
various environmental signals and translated by the controller into the
more elementary instructions that Level II can understand.
Manipulator
The manipulator consists of segments that may be jointed and that
move about, allowing the robot to do work. The manipulator is the arm
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Level III: Main Control
High-level instruction interpreter.
Level II: Path Control
Coordinates robot path movement.
Level I: Actuator Control
Controls individual robot actuators.
Figure 2-5. The three basic levels of hierarchical control.